The second chart makes a small change look insignificant, when in fact it’s quite significant in terms of it’s ability to trap heat. The point here is that small changes in the relative percentage of CO2 concentration have significant impacts – the scales in the first chart are not alarmist at all – they are simply showing a scale where you can visualize the data.

Reference for warming rates: http://earthguide.ucsd.edu/globalchange/global_warming/03.html

since there are two data points tacked on your, assumed accurate, historic data that are, at the best, fictions of the imagination of the charters, you are wrong on that account also.

A great example is the Wilkins ice shelf in Antarctica. The ice self is often portrayed as 1/5 of Antarctica and is about to break free of the continent. This done again to scare people in to thinking their favorite tropical island is about to be flooded. But how would people react when the correct picture is presented. Lets use the US as an example. I report that 1/5th of the US is about to fall in to the ocean. This area is called Cape Cod but it’s not the whole cape but just the tip. Americans wouldn’t take my claim seriously since most people know or can look at a US map and see Cape Cod isn’t 1/5th of the US. People aren’t going to do this with Antarctica.

Perhaps you are right, but the post was not about problems with the underlying data, it was about “chartmanship.” And I don’t see anything wrong with the chart at all as a clear and accurate presentation of the data.

Whether the data itself is faulty is another issue, entirely separate from any issues of poor “chartmanship” addressed in the post.

ed, I’m afraid it is you who is way off with your lead analogy. Lead is poisonous, CO2 isn’t. And the first graph is not accurate, for the reason I’ve explained.

“The first graph, if accurate, simply shows that current and projected CO2 concentrations are way higher than they have been for hundreds of thousands of years, which is exactly what it is trying to show.”

The data on CO2 concentrations for the last few hundreds of thousands of years is not in agreement. That is, it is contentious with different factions believing in different max and min numbers based on different proxies. This group simply assumes the IPCC/Ice Core faction is correct and then makes a chart with the best propaganda techniques.

With what is reasonably supported from other proxies, the idea that the earth’s CO2 level would have been virtually monotonic between 200 and 280 ppm while the earth went through multiple ice ages with warm interregnums with temps comparable to now is simply ludicrous.

While Ed’s point above is valid (on % composition), we don’t actually appear to be entering “terra incognita”, just moving back up the slope of CO2 concentration to where it was roughly at the time of the dinosaurs’ extinction – just a few days ago, geologically speaking.

OT, but thinking about “deep time” reminded me of a helpful time scale chart that adds some perspective to discussions about “the way things are”; I found it at an economics site called The Sceptical Optimist:

Why would you think that the total percentage of atmosphere is the relevant quantity? Would you say the same thing for other pollutants or poisons? (e.g. these paint chips are only .1% lead, so I don’t know why everyone is so upset that kids are eating them!)

The first graph, if accurate, simply shows that current and projected CO2 concentrations are way higher than they have been for hundreds of thousands of years, which is exactly what it is trying to show. The message is that we are entering terra incognita as far as CO2 levels. What’s the problem with that? Wouldn’t you agree?

Again, good work overall, but you missed badly on this one, as far as I can see. Am I missing something?